In recent years, a semiconductor device using a thin film transistor has been widely applied to a large-sized liquid crystal display device such as a television as well as a portable terminal such as a cellular phone, and also has been developed actively.
A droplet discharging method has various advantages such as no need for a mask, easy increase in the size of a substrate, high usability of a material, being possible to decrease the amount of facility investment and miniaturize the size of manufacturing apparatus. Therefore, a droplet discharging method is applied to manufacturing a wiring, an electrode and the like of a color filter or a plasma display.
In the conventional method for manufacturing a semiconductor device, a considerably complex step is used for forming a pattern of a circuit or the like. For example, a step of manufacturing a semiconductor device in which a wiring in a lower layer and a wiring in an upper layer are connected to each other with an insulating film therebetween is briefly described hereinafter.
Initially, a conductive film which is to be a base of a wiring is formed over an insulating surface, and a resist is formed over the entire surface of the insulating film by using spin coating. Subsequently, a region which is used for a wiring in the conductive film is specified, and a resist pattern is formed by light-exposure and development to form a desired wiring by selectively etching the conductive film. Then, an insulating film is formed over the wiring by CVD, sputtering, spin coating or the like, and a resist is formed over the insulating film. Then, the insulating film is selectively etched to form an opening so that the wiring in a lower layer is exposed by using the resist on which light-exposure and development treatment is performed as a mask as above. Then, a conductive film is formed to fill the opening and a resist is formed over the conductive film. Subsequently, the conductive film is etched to form a wiring in an upper layer connected to the wiring in a lower layer by using the resist on which light-exposure and development treatment is performed as a mask.